diff --git a/knip.config.ts b/knip.config.ts
index ff55bf1a00..286a72bfd2 100644
--- a/knip.config.ts
+++ b/knip.config.ts
@@ -90,7 +90,10 @@ const config: KnipConfig = {
     'src/extensions/core/rerouteNode.v2.ts',
     'src/extensions/core/slotDefaults.v2.ts',
     // W6.P3.D — defineWidget+mount showcase port (D-widget-converge / A12).
-    'src/extensions/core/webcamCapture.v2.ts'
+    'src/extensions/core/webcamCapture.v2.ts',
+    // W6.P4.D — canvas-units canary + escape-hatch annotation example
+    // (D-coord-space / A13).
+    'src/extensions/core/coordSpaceDemo.v2.ts'
   ],
   vite: {
     config: ['vite?(.*).config.mts']
diff --git a/src/extensions/core/coordSpaceDemo.v2.ts b/src/extensions/core/coordSpaceDemo.v2.ts
new file mode 100644
index 0000000000..84fd0a6194
--- /dev/null
+++ b/src/extensions/core/coordSpaceDemo.v2.ts
@@ -0,0 +1,76 @@
+/**
+ * CoordSpaceDemo — canary example for the D-coord-space PICK
+ * (W6.P4 ACCEPTED 2026-05-18, Axiom A13 Single Coordinate Space).
+ *
+ * Shows three things:
+ *
+ * 1. **The default — canvas units everywhere.** `node.getPosition()` /
+ *    `getSize()` / `setPosition()` / `setSize()` all speak canvas units.
+ *    Zoom and pan don't perturb the numbers; devicePixelRatio is
+ *    invisible. This is the path 96%+ of extensions should ever take.
+ *
+ * 2. **The escape-hatch — explicit + annotated.** For the legitimate
+ *    cases that need screen-space coords (custom GPU canvas, floating
+ *    overlay anchored to absolute browser coords, hi-DPI export math),
+ *    drop to `window.app.canvas.{ds,canvas}` + `window.devicePixelRatio`.
+ *    Every escape-hatch use site MUST carry the
+ *    `// escape-hatch — see D-coord-space.md` comment so reviewers
+ *    (human or AI) can see the dependency is deliberate.
+ *
+ * 3. **The cliff — what's NOT on the public surface.** No
+ *    `node.getScreenPosition()`, no `node.getCSSPosition()`, no
+ *    `space: 'client' | 'css'` parameter, no branded `ClientPoint`
+ *    type. Reaching for any of those is a sign the author wants the
+ *    escape-hatch.
+ */
+
+import { defineExtension, defineNode, type NodeHandle } from '@/extension-api'
+
+defineNode({
+  name: 'Comfy.CoordSpaceDemo.V2',
+
+  nodeCreated(node: NodeHandle) {
+    // ── (1) Default path: canvas units, no conversion needed ──────────
+    const [x, y] = node.getPosition() // canvas units
+    const [w, h] = node.getSize() //     canvas units
+
+    // Move a node 16 canvas units down-and-right of its current spot.
+    // No /scale, no *scale, no devicePixelRatio — the runtime owns it.
+    node.setPosition([x + 16, y + 16]) // canvas units
+
+    // Reserve a minimum size — also canvas units; zoom doesn't matter.
+    if (w < 200) node.setSize([200, h])
+  }
+})
+
+defineExtension({
+  name: 'Comfy.CoordSpaceDemo.V2.Escape',
+
+  setup() {
+    // ── (2) Escape-hatch path — explicit + annotated ──────────────────
+    //
+    // Use case: extension wants to draw a 2x-pixel-density preview
+    // thumbnail PNG of the visible viewport. PNG export needs *device
+    // pixels* (so the saved image is crisp on hi-DPI displays); the v2
+    // public surface does not expose dpr or screen-pixel sizing.
+    //
+    // The escape-hatch is the same shape extension authors are already
+    // using today (213 dpr hits across 27 repos in the W6.P4.R1 sweep).
+
+    // escape-hatch — see D-coord-space.md § Documentation contract
+    const dpr = window.devicePixelRatio
+    // escape-hatch — see D-coord-space.md § Documentation contract
+    const canvas = globalThis.app?.canvas
+    if (!canvas) return
+    // escape-hatch — see D-coord-space.md § Documentation contract
+    const { scale } = canvas.ds
+    // escape-hatch — see D-coord-space.md § Documentation contract
+    const rect = canvas.canvas.getBoundingClientRect()
+
+    // From here, the author owns dpr math + canvas↔screen conversions.
+    // The runtime makes no stability promise about ds.scale or the
+    // shape of window.app.canvas — escape-hatch is intentionally
+    // fragile per Axiom A13.
+    void { dpr, scale, rect }
+  }
+})